Originally Posted by Vee

I have been following this thread for a while now. I was hoping for an update or resolution...

Originally Posted by Vee

I know you replaced your CRANKshaft position sensor, but I believe you should investigate replacing your CAMshaft position sensor.

...

Originally Posted by thriftyshirt

I am a new (old) Jag owner, I bought a 1997 XJ6L locally from a Craigslist ad about 3 months ago. An elderly couple owned it for the last 17 years, having bought it at a Jag dealership as a "pre-owned" model in 2000 (I checked vehicle history). It had about 150,000 miles on it, and just over 152,000 now.

It drove like a dream for the first month and a half, and I was super excited to be a first time jag owner. I had the fluids changed, and fixed a bunch of small cosmetic issues inside and out, but did not have any serious work done and started driving it as a daily.

About about 6 weeks of ownership "the problem" starts. The problem is a random "cutting out" of the engine. Throttle position and RPM does not matter, it will do it under load, at speed with no load, and at idle. The engine feels like it just "turns off" for a second, and then comes back on. As long as I have some RPMS or road speed, it kicks right back in and keeps going. But at idle, or low rpm it will cause a stall. When it happens the dash, aircon, power steering, brakes, and internal electronics all keep working fine.

So, I found this forum and started looking for a solution based on others with a similar experience. Here is what I've done so far:

1. Took the car to a local mechanic I trust. He scanned it and found engine misfire codes, so he suspected the coil packs. They are newish, not the originals, and he thinks replaced in the last year or so (this is also what the previous owner told me), but they are not OEM. He looks them up, and Jaguar wants $420 each for 6 packs. I tell him that's a death sentence for me, as I cannot afford a ~$2400 repair. I ask him to check the spark plugs for age/brand, thinking maybe the previous owners put in "better" plugs that are not compatible. He checks them and finds that 2 are not seated fully (hand tight at best, not torqued down) and these are the two coils misfiring. These two show evidence of blow-by. Also, all the plugs are old and crusty. He replaces all of them with the correct Champion plugs (RC12Ycc) gapped to .035 as the manual recommends. The car runs perfectly afterwards....for a week.
2. I go to start on a Saturday morning and get a "no-crank" scenario. Gear shift interlock won't budge, and no remote keyless or any central locking functions are working. I check all the fuses, and find no issues. I research, and narrow it down to the "body processor module". I buy an old one from a working car off ebay and install myself. The car works again! But central locking is still dead (no keyless, lock button does nothing, locks won't go up and down with key in door, etc.) I don't care, though! My jag drives again!....for four days.
3. The original problem shows up again. Same symptoms, nothing has changed. Except this time, I can't get it out of the driveway because it insta-stalls upon startup. Engine cranks, catches runs for a few seconds, then stalls. I call a friend/mechanic who comes to my house and hooks up his pricey diagnostic tools and reads air/fuel sensors. He says the MAF is dead, and showing 0 signal. He suggest that the MAF cutting in and out on its way to death could cause my previous symptoms, and now its gone completely. I look up an OEM MAf, Jag wants $1200. F that. I buy an old ('97) MAF pulled from a working car from a parts dealer locally. Install myself, also clean the whole air intake (a little dusty), replace air filter (totally dusty, with leaves in it), and clean throttle body (not too bad). My car works again!...for 1 whole day.
4. Confident I've found the problem and fixed it myself, I take the car and my fam to my father's home (about an hour away) on fathers day. It drives perfectly the whole way there. When it's time to leave, it returns to insta-stalling, with the same "cutting out" symptoms from before. My father and I pull all the spark plugs and check the gaps (no issues), coil packs appear to be seated correctly, we cannot find any loose or frayed wiring. We check that all ground points are clean and tight. No solution. My father drove my family home, and I arranged for a tow to a shop close to my dad's house that he recommended, because the owner/manager is a friend. Its an independent shop, but "european specialists." I called first, and spoke with his friend who assured me he knew the model and the quirks.
5. I will not go into detail about this experience, but it was negative. The shop kept it for 6 days, and diagnosed it with a failing/intermittent Crank Position Sensor. $470 later, I have a brand new CPS on the car. I pick it up, drive it home, angry at the expense but relieved to finally have my car normal again, and sure that this expensive shop made an accurate diagnosis. Then it stalls out 5 minutes from home. Same symptoms.
6. I read forums. I read manuals. I read posts from the UK, yahoo ansers, service bulletins, etc. What have I not done yet? Fuel Filter! That might cause this symptom if its super old/clogged. Considering the spark plug situation, it probably wasn't replaced recently. I pay a local shop I trust $40 to put it on a lift and replace the filter with an OEM Jag one ($30). The old filter has fuel in it that looks like pond water. With my fresh new filter, I drive away with perfect idle, perfect performance, until "the problem" returns again 15 minutes later.

At this point, I have no idea what else to check. My wife is already telling me to dump this car, but I love it (when it works). When the engine cuts out, it feels like someone is "flicking a light switch on and off", and it has gone days in a row (with longer drives) without having "the problem".



Most of the time, a code is not stored when this happens. The CEL will "blip" on when the engine cuts out, but then turn off again when it comes back on. However, it has stored codes on occasion. Here is a list of what I've pulled from it, with the date:

• 5/12/17 - P0420, B30F4, P13B0
• 6/17/17 - P1790, P0727
• 6/28/17 - P0300, P0305, P1790

Here's a video of what the dash looks like while the "problem" is present, shot today: https://youtu.be/omqKJtZO0Fo (ignore the transmission light, its in "limp mode" because I had just restarted it from a stall. Limp mode always goes away after it sits for a minute.)


The loss of the BPM and Central Locking at the same time makes me think an electrical short somewhere, but where? No fuses are blown, I went through them all on two separate occasions with a multimeter.



Please help!

Originally Posted by thriftyshirt

I am a new (old) Jag owner, I bought a 1997 XJ6L locally from a Craigslist ad about 3 months ago. An elderly couple owned it for the last 17 years, having bought it at a Jag dealership as a "pre-owned" model in 2000 (I checked vehicle history). It had about 150,000 miles on it, and just over 152,000 now.

It drove like a dream for the first month and a half, and I was super excited to be a first time jag owner. I had the fluids changed, and fixed a bunch of small cosmetic issues inside and out, but did not have any serious work done and started driving it as a daily.

About about 6 weeks of ownership "the problem" starts. The problem is a random "cutting out" of the engine. Throttle position and RPM does not matter, it will do it under load, at speed with no load, and at idle. The engine feels like it just "turns off" for a second, and then comes back on. As long as I have some RPMS or road speed, it kicks right back in and keeps going. But at idle, or low rpm it will cause a stall. When it happens the dash, aircon, power steering, brakes, and internal electronics all keep working fine.

So, I found this forum and started looking for a solution based on others with a similar experience. Here is what I've done so far:

1. Took the car to a local mechanic I trust. He scanned it and found engine misfire codes, so he suspected the coil packs. They are newish, not the originals, and he thinks replaced in the last year or so (this is also what the previous owner told me), but they are not OEM. He looks them up, and Jaguar wants $420 each for 6 packs. I tell him that's a death sentence for me, as I cannot afford a ~$2400 repair. I ask him to check the spark plugs for age/brand, thinking maybe the previous owners put in "better" plugs that are not compatible. He checks them and finds that 2 are not seated fully (hand tight at best, not torqued down) and these are the two coils misfiring. These two show evidence of blow-by. Also, all the plugs are old and crusty. He replaces all of them with the correct Champion plugs (RC12Ycc) gapped to .035 as the manual recommends. The car runs perfectly afterwards....for a week.
2. I go to start on a Saturday morning and get a "no-crank" scenario. Gear shift interlock won't budge, and no remote keyless or any central locking functions are working. I check all the fuses, and find no issues. I research, and narrow it down to the "body processor module". I buy an old one from a working car off ebay and install myself. The car works again! But central locking is still dead (no keyless, lock button does nothing, locks won't go up and down with key in door, etc.) I don't care, though! My jag drives again!....for four days.
3. The original problem shows up again. Same symptoms, nothing has changed. Except this time, I can't get it out of the driveway because it insta-stalls upon startup. Engine cranks, catches runs for a few seconds, then stalls. I call a friend/mechanic who comes to my house and hooks up his pricey diagnostic tools and reads air/fuel sensors. He says the MAF is dead, and showing 0 signal. He suggest that the MAF cutting in and out on its way to death could cause my previous symptoms, and now its gone completely. I look up an OEM MAf, Jag wants $1200. F that. I buy an old ('97) MAF pulled from a working car from a parts dealer locally. Install myself, also clean the whole air intake (a little dusty), replace air filter (totally dusty, with leaves in it), and clean throttle body (not too bad). My car works again!...for 1 whole day.
4. Confident I've found the problem and fixed it myself, I take the car and my fam to my father's home (about an hour away) on fathers day. It drives perfectly the whole way there. When it's time to leave, it returns to insta-stalling, with the same "cutting out" symptoms from before. My father and I pull all the spark plugs and check the gaps (no issues), coil packs appear to be seated correctly, we cannot find any loose or frayed wiring. We check that all ground points are clean and tight. No solution. My father drove my family home, and I arranged for a tow to a shop close to my dad's house that he recommended, because the owner/manager is a friend. Its an independent shop, but "european specialists." I called first, and spoke with his friend who assured me he knew the model and the quirks.
5. I will not go into detail about this experience, but it was negative. The shop kept it for 6 days, and diagnosed it with a failing/intermittent Crank Position Sensor. $470 later, I have a brand new CPS on the car. I pick it up, drive it home, angry at the expense but relieved to finally have my car normal again, and sure that this expensive shop made an accurate diagnosis. Then it stalls out 5 minutes from home. Same symptoms.
6. I read forums. I read manuals. I read posts from the UK, yahoo ansers, service bulletins, etc. What have I not done yet? Fuel Filter! That might cause this symptom if its super old/clogged. Considering the spark plug situation, it probably wasn't replaced recently. I pay a local shop I trust $40 to put it on a lift and replace the filter with an OEM Jag one ($30). The old filter has fuel in it that looks like pond water. With my fresh new filter, I drive away with perfect idle, perfect performance, until "the problem" returns again 15 minutes later.

At this point, I have no idea what else to check. My wife is already telling me to dump this car, but I love it (when it works). When the engine cuts out, it feels like someone is "flicking a light switch on and off", and it has gone days in a row (with longer drives) without having "the problem".



Most of the time, a code is not stored when this happens. The CEL will "blip" on when the engine cuts out, but then turn off again when it comes back on. However, it has stored codes on occasion. Here is a list of what I've pulled from it, with the date:

• 5/12/17 - P0420, B30F4, P13B0
• 6/17/17 - P1790, P0727
• 6/28/17 - P0300, P0305, P1790

Here's a video of what the dash looks like while the "problem" is present, shot today: https://youtu.be/omqKJtZO0Fo (ignore the transmission light, its in "limp mode" because I had just restarted it from a stall. Limp mode always goes away after it sits for a minute.)


The loss of the BPM and Central Locking at the same time makes me think an electrical short somewhere, but where? No fuses are blown, I went through them all on two separate occasions with a multimeter.



Please help!